Regulations related to renewable fuels provide an example of how product requirements can change over time. During the next decade, the United States, Canada, and the European Union have increased and/or are likely to increase the required amount of product from renewable sources that is contained in transportation fuels. Based on such regulatory requirements, fuels from vegetable, animal, or algae sources such as “biodiesel” will become increasingly important as a refinery product. As a result, methods are needed that will allow existing refinery equipment to produce suitable transportation fuels that incorporate increasing amounts of renewable components.
Unfortunately, the differences in chemical composition between renewable carbon sources and mineral sources poses some difficulties for refinery processing. For example, typical biologically-derived sources for fuels have oxygen contents of 1 wt % or more, and possibly as much as 10 to 12 wt % or more. Conventional hydroprocessing methods can remove oxygen from a feedstock, but the by-products from deoxygenation can lead to catalyst poisoning and/or contaminant build-up in a reaction system.